In the areas of product or part manufacturing, machining, and/or repair, there are many times that a part or product must be held firmly to be worked on. One method of doing so includes the use of what is commonly known as a vise. Vise(s) are typically used in order to temporarily hold one or more objects so that work can be performed on the one or more objects. There are a number of different types or species of vise(s). For example, traditional table top mounted vises, such as a mechanics vise, have existed for years. A typical vise is composed of a stationary jaw with a base that can be mounted to a surface. There is a moveable jaw and a guide bar(s) that allows the moveable jaw to move smoothly toward and away from the stationary jaw. Each jaw has a clamping surface for holding a work piece. Further, the vise has a screw threaded bar (referred to herein as the screw or spindle) and lever system which operates the moveable jaw. The screw or spindle typically has a relatively fine pitched thread which provides a large mechanical advantage such that a relatively small amount of torque applied to the lever produces a large clamping force between the jaws. The screw or spindle moves the moveable jaw whereby the fine pitch required for the large mechanical advantage causes the jaw to move a very small distance with each turn. Thus, adjusting the jaws to different opening sizes for clamping of relatively thin and subsequently relatively thick items (or vise versa) requires numerous turns of the lever attached to the screw or spindle.
There are many types of vises used for varying applications. For example, the typical mechanics vise or industrial vise is made of a heavy metal construction and is typically firmly mounted to, for example, a table or bench top so as to be stationary in at least height and location, although some conventional vises may be able to rotate at their base or base plate in a circular motion. A conventional mechanics bench vise typically has the following major parts: a movable jaw, a stationary jaw, a screw or spindle, a vise main nut, and a base plate. The moveable jaw may be, for example, a square or round sliding bar. It is usually made from gray or ductile iron and may include a steel jaw insert. The stationary jaw may mounted to or be integrally formed with a base plate and securely mounted to a table or bench. The stationary jaw may include a square or round opening to allow moveable jaw's square or round sliding bar to move in and out of it. It is usually made from gray or ductile iron and may also include a steel jaw insert.
The movement of the movable jaw is generally effected by rotating a tommy bar attached to the main screw or spindle which, in turn, rotates the screw or spindle. This causes the screw or spindle to advance through the fixed jaw by virtue of the co-operating screw-threads therein which means that the moveable jaw (which is axially fixed to the screw or spindle) advances toward or away from the fixed jaw (depending upon the direction of rotating the tommy bar) a small amount at a time based on the spacing of the screw threads.
When it is desired to clamp an object in the vise's jaws, the user must hold the object in the space between the jaws whilst turning the tommy bar in order to advance the moveable jaw toward the fixed jaw (and the object held in between). When the moveable jaw reaches the object and holds it against the fixed jaw, clamping is effected. It can be rather slow to advance the moveable jaw to clamp the object effectively, especially if the jaws are wide apart initially. Indeed, when the jaws are wide open but it is desired to clamp a small object, it is time-consuming to wind the screw until the jaws approach the object. Furthermore, when it is desired to release the object from the jaws, depending on the size and shape of the object, the tommy bar may have to be turned for an inconveniently long time in order to move the moveable jaw sufficiently away from the fixed jaw in order to release the object.
Recent developments in vises have allowed for a quicker adjustment of the vise. The vise designs have generated solutions that allow the fine pitched thread mechanism to be disengaged while allowing rough adjustments of the vise head. For example, the “slowly adjustable” problem may be alleviated by a known type of vise which incorporates a “quick-release” mechanism. Instead of the screw-threaded main vise screw permanently engaging with a screw-thread on the interior of the fixed jaw, the fixed jaw screw-thread comprises a half screw-threaded main nut which is, normally, urged into engagement with the main vise screw, for example by means of a spring. When it is desired to actuate the “quick-release” mechanism, a lever pushes the main nut away from the main vise screw by overcoming the force of the spring. In this way the main vise screw is released from engagement with the main nut, allowing the main vise screw to be moved axially free of the fixed jaw. The lever is actuated, on demand, by the vise operator which can be inconvenient since he may already need his hands to operate the tommy bar and/or support the object which is about to be released from or indeed clamped in, the vise.
Furthermore, where the traditional vise had a female thread integral to the stationary jaw that engaged with the screw, some new vises may have a female thread part separate from the stationary jaw. The separate part is called a semi-thread because it engages with less than 180.degree of the screw. The semi-thread rides in a track system in the stationary head such that a mechanism can disengage the semi-thread from the screw as desired. With the semi-thread disengaged, a user can slide the moveable jaw to the approximate opening size required for application at hand. A separate lever on the moveable jaw turns a bar or shaft that subsequently disengages the semi-thread from the male thread. The semi-thread is typically spring loaded into engagement with the male thread. With the semi-thread disengaged the jaw opening can be adjusted to the desired size. This system is a vast improvement over previous vises, increasing the efficiency of use.
However, the new quicker action vises are not without problems, because they typically have merely a spring which presses the main nut into engagement with the threaded screw, the threads must be somewhat radial to reduce the tendency for the threads to have a radially outward component of reaction, causing the half threaded main nut potentially to spring off the vise screw, when the tommy bar is very tightly clamped. Radial screw-threads are expensive to produce and cannot satisfactorily be roll-formed. Further, these new type of vises typically require two levers to operate. One lever is required to turn the bar and subsequently disengage the semi-thread. While holding this lever in position to keep the semi-thread out of engagement, the jaw opening can be adjusted to the appropriate size by pulling or pushing on the moveable jaw. To apply large clamping force the user must let go of this first lever and grab the second lever that turns the screw to apply a significant clamping force. On the other hand, some quick action vises do not allow the semi-thread main nut to be engaged rather than disengage when the tommy bar is turned in the untightening direction so that the vise movable jaw may be slowly backed away from a work piece.
Therefore, a need exists for an improved apparatus and method of vise clamping that would allow a user to quickly adjust the opening size of the jaws and apply clamping force to the jaw through the use of one lever, while having a means for selectively holding the main nut engaged while loosening the vise jaws a small amount at a time. It is therefore an object of the present invention to provide an improved mechanism for rapidly adjusting the relative position of the jaws of a vise as a primary action while having a slow adjustment of the vise jaws as a secondary action, which alleviates the above-described problems.